Exposure to less than one part per billion of the most commonly used herbicide in the U.S. can feminize male frogs, according to a new study. The findings, published today in the Proceedings of the National Academy of Sciences, suggest that concentrations of chemicals considered safe for humans can have insidious effects on amphibians and could be contributing to the global decline in their populations.

Tyrone B. Hayes of the University of California, Berkeley, and colleagues studied the ef

Life originated on the Earth more than 3.5 billion years ago. However, the scientists are still disputing over the possible sources of the life origin. The matter is that life on our planet evolved from the molecular level to the level of bacteria organisms within 0.5 – 1 billion years, this period being very short for such an important evolutionary step. The researchers are still racking the brains over this mystery. One of the popular hypothesis asserts that some germs of life have been brought to

In the city, frogs do not feel as comfortable as in the wild nature because of dirty water, a lack of food, and dangers at every turn. That is why the life of frogs in urban areas is shorter. However, they do not leave these habitats, but adapt to them. Apparently, there are two ways to adapt: either become more tolerant or increase the number of progeny.

Every spring from 1998 to 2001, Elena A. Severtseva and her colleagues from the Biological Faculty of the Moscow State University

They did not work with people; instead they examined rats of two lines. The rats of the first line were more anxious by their nature. Some rats were kept in groups, while others were kept in single cages. It is known that solitude is an unfavourable factor for rats.

The animals were given 0.1% solution of caffeine when they were thirsty. To measure the anxiety level the researchers examined the behaviour of animals in a cage with two sections: light and dark. More time the animal sp

Fungi that trigger allergies go under scrutiny.

Industry researchers have produced the largest study yet of airborne fungi in US buildings. The fungal fingerprints may help scientists understand their role in triggering allergies and other medical conditions.

Exposure to spores released by moulds is known to cause or worsen allergies and trigger asthma episodes in sufferers. Spores enter buildings through air ducts or open windows and can thrive in moist indoor conditions.

A crayfish’s urine scares off its enemies.

A well-timed blast of urine is the key to winning a crayfish fight, say researchers. The chemical aggression intimidates opponents into backing down.

Ecologist Thomas Breithaupt injected freshwater crayfish with a dye that made their urine glow green. He and his colleague Petra Eger staged fights between blindfolded crayfish ( Astacus leptodactylus ), to replicate the animals’ nocturnal habits1.

The eventual